Openly gay pop star George Michael has said he was invited to take part in the Leveson inquiry into British media standards and has branded the official who said he wasn’t invited as a ‘liar’.

The Leveson inquiry has dominated the headlines in Britain for months – it’s looking at the culture, practice and ethics of the press with Rupert Murdoch’s media empire particularly in the firing line after his national Sunday paper News International was caught hacking people’s phones.

In a series of Twitter posts, Michael said: ‘I was asked to talk to the Leveson inquiry, but I declined. It's all bullshit.

‘It has been several years since two hacking journalists were sent to prison for bugging the royal family. They remain the only people who have been tried in the criminal courts.

‘After all these years, and all the crimes committed by journos, editors, the police force and MPs the best can do is “enquiry” after inquiry, and no actual criminal prosecutions?

‘Shame on our political system for it's refusal to take this further. The day they make this sham real and start genuinely prosecuting people I would more than happy to help. :)... till then, what's the point.’

But after Press Association reported that the Leveson Inquiry had never asked Michael to participate, he changed his attack to the inquiry officials themselves.

In a series of tweets in last hour (on 9 May) he said: ‘I just spoke to my lawyers. The “spokesman” who denied ever having approached me on behalf of the Leveson committee should know that my lawyers still have the letter in which they invited me to join them.

‘So, there you have it. Would they like to apologise? For effectively calling me a fantasist? I think we are all on the same side in trying to change the laws and protect everybody from the likes of Rupert Murdoch. I'd prefer to believe that. Otherwise we are looking at liars being investigated by liars. And I know the vast majority of people on that committee are better than that.’

When someone tweeted @georgemichael to point out Rupert Murdoch is one of his followers, he claimed: ‘Well it makes a change from him paying other people to follow me, which, believe me, he did.’